Actually, I would say that Sony barely survived this generation because of those deals. The PS3 was too expensive...there was little to show the benefits of it over the Xbox 360...and the 360 was getting all the big games too. Then Sony's exclusives and 1st party games helped differentiate they system. Imagine what might have been if Sony hadn't done that with all the blunders it did this generation.
Most of Sony's blunders happend in the early years of the PS3. As time went on, Sony forged bigger and better exclusive deals with developers. A few of those developers were bought out by Sony, most notably Sucker Punch (inFamous) and Media Molecule (LittleBigPlanet).
Contrast this with Microsoft, who had some of the best exclusives in the early years of the Xbox 360, but then they completely switched focus to Kinect. Most of their exclusive deals have fallen by the wayside in favor of more Halo, Gears of War, Forza, and Kinect games. Gears of War was probably Microsoft's biggest exclusive series this gen, but they haven't done much else since.
Hopefully Microsoft will balance things out with their next system, but it's never too late to get the ball rolling now.